<?php
/**
 * Copyright since 2007 PrestaShop SA and Contributors
 * PrestaShop is an International Registered Trademark & Property of PrestaShop SA
 *
 * NOTICE OF LICENSE
 *
 * This source file is subject to the Open Software License (OSL 3.0)
 * that is bundled with this package in the file LICENSE.md.
 * It is also available through the world-wide-web at this URL:
 * https://opensource.org/licenses/OSL-3.0
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@prestashop.com so we can send you a copy immediately.
 *
 * DISCLAIMER
 *
 * Do not edit or add to this file if you wish to upgrade PrestaShop to newer
 * versions in the future. If you wish to customize PrestaShop for your
 * needs please refer to https://devdocs.prestashop.com/ for more information.
 *
 * @author    PrestaShop SA and Contributors <contact@prestashop.com>
 * @copyright Since 2007 PrestaShop SA and Contributors
 * @license   https://opensource.org/licenses/OSL-3.0 Open Software License (OSL 3.0)
 */

declare(strict_types=1);

namespace PrestaShop\PrestaShop\Core\FeatureFlag\Layer;

use InvalidArgumentException;
use PrestaShop\PrestaShop\Core\FeatureFlag\FeatureFlagSettings;
use PrestaShop\PrestaShop\Core\FeatureFlag\TypeLayerInterface;

class EnvLayer implements TypeLayerInterface
{
    /**
     * {@inheritdoc}
     */
    public static function getTypeName(): string
    {
        return FeatureFlagSettings::TYPE_ENV;
    }

    /**
     * {@inheritdoc}
     */
    public function isReadonly(): bool
    {
        // It's always NOT editable via Env layer!
        return true;
    }

    /**
     * Retrieve the const name of this feature flag.
     */
    public function getConstName(string $featureFlagName): string
    {
        return FeatureFlagSettings::PREFIX . strtoupper($featureFlagName);
    }

    /**
     * {@inheritdoc}
     */
    public function canBeUsed(string $featureFlagName): bool
    {
        // Check if PS_FF_{featureFlag's name} is on Env variable.
        return getenv($this->getConstName($featureFlagName)) !== false;
    }

    /**
     * {@inheritdoc}
     */
    public function isEnabled(string $featureFlagName): bool
    {
        return $this->canBeUsed($featureFlagName)
            && filter_var(getenv($this->getConstName($featureFlagName)), \FILTER_VALIDATE_BOOLEAN);
    }

    /**
     * {@inheritdoc}
     */
    public function enable(string $featureFlagName): void
    {
        throw new InvalidArgumentException(sprintf('We cannot change status of the env feature flag %s.', $featureFlagName));
    }

    /**
     * {@inheritdoc}
     */
    public function disable(string $featureFlagName): void
    {
        throw new InvalidArgumentException(sprintf('We cannot change status of the env feature flag %s.', $featureFlagName));
    }
}
